To somehow backup this this claim:
http://store.steampowered.com/app/311340/
http://store.steampowered.com/app/287700/
Personally, I'm not THAT much interested in MGS, but even I can notice that this is extraordinary good way how to promote the game.
That game was some really good fuel for console vs pc flamewars and after this, it's doing even better at that = free advertising.
Many gaming magazines which already informed quite a lot about it now have even more stuff to write about = more free advertising.
Many people spread the word about this, let it be in casual talk about games, while thinking if buying PS4 is a good choice or not, maybe someone writes about it on some forums or their small blog = you guessed it, even more free advertising.
Even if it was unintentional, it does the job really well. And if it was intentional, then that guy who came with this idea is definitely getting promoted.
Advertising